Characterization and comparative expression analysis of CUL1 genes in rice

Abstract

Cullin-RING E3 ubiquitin ligase (CRL) complex is known as the largest family of E3 ligases. The most widely characterized CRL, SCF complex (CRL1), utilizes CUL1 as a scaffold protein to assemble the complex components. To better understand CRL1-mediated cellular processes in rice, three CUL1 genes (OsCUL1s) were isolated in Oryza sativa. Although all OsCUL1 proteins exhibited high levels of amino acid similarities with each other, OsCUL1-3 had a somewhat distinct structure from OsCUL1-1 and OsCUL1-2. Basal expression levels of OsCUL1-3 were much lower than those of OsCUL1-1 and OsCUL1-2 in all selected samples, showing that OsCUL1-1 and OsCUL1-2 play predominant roles relative to OsCUL1-3 in rice. OsCUL1-1 and OsCUL1-2 genes were commonly upregulated in dry seeds and by ABA and salt/drought stresses, implying their involvement in ABA-mediated processes. These genes also showed similar expression patterns in response to various hormones and abiotic stresses, alluding to their functional redundancy. Expression of the OsCUL1-3 gene was also induced in dry seeds and by ABA-related salt and drought stresses, implying their participation in ABA responses. However, its expression pattern in response to hormones and abiotic stresses was somehow different from those of the OsCUL1-1 and OsCUL1-2 genes. Taken together, these findings suggest that the biological role and function of OsCUL1-3 may be distinct from those of OsCUL1-1 and OsCUL1-2. The results of expression analysis of OsCUL1 genes in this study will serve as a useful platform to better understand overlapping and distinct roles of OsCUL1 proteins and CRL1-mediated cellular processes in rice plants.

Keywords

OsCUL1 CRL Ubiquitination Hormones Abiotic stresses

Electronic supplementary material

The online version of this article (doi:10.1007/s13258-017-0622-8) contains supplementary material, which is available to authorized users.

Notes

Acknowledgements

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2016R1D1A1B03930213), by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through Agri-Bio industry Technology Development Program funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (115081-2), and by the Strategic Initiative for Microbiomes in Agriculture and Food, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea (916007021HD040).

Compliance with ethical standards

Conflict of interest

Sang-Hoon Kim declares that he does not have conflict of interest. Og-Geum Woo declares that she does not have conflict of interest. Hyunsoo Jang declares that he does not have conflict of interest. Jae-Hoon Lee declares that he does not have conflict of interest.

Ethical approval

This article does not contain any studies with human subjects or animals performed by any of the authors.